Merge pull request #175 from jonschlinkert/master

stopgap for options.assets until we decide on a direction. add test files
Merge pull request #176 from jonschlinkert/master

get travis passing
add `{{assets}}` to test files
fixing the engine factory to provide the engine properly
Merge pull request #180 from doowb/master

Fixing engine factory to return the underlying engine properly.
bumping version and updating changelog and docs
Merge pull request #181 from doowb/master

Bumping version and updating changelog and docs
Merge remote-tracking branch 'refs/remotes/github.com/master'
update README with more info on assemble object, methods, partials and helpers